Replacing bolts ?? Help

[Spy]

Hi all,

I am in the process of choosing a new, sportier exhaust for my 996 Turbo.

As part of this, I would like to replace as many bolts as reasonably and practically possible with Stainless Steel versions.

Is there a diagram or list anywhere of all the bolts around the exhaust, heat shields, turbos etc and their sizes ?

Thanks

 

[Jenik1914]

Hi try 2010.cannell.co.uk lots of Porsche manuals and stuff there.

 

[Richard_Hamilton]

I don't think the Turbo manuals are on the Cannell site.

See here for the parts list: http://www.porscheclubgbforum.com/tm.asp?m=230706

 

[Spy]

Thanks Richard...as always []

 

[Spy]

I don't know if I am being a little dense but I have just looked at the PET manual and it doesn't say what sizes I need.

For example, on PDF page 60 which shows the exhaust, part no 7 which is the bolt that fixes the exhaust cat to the turbo, is just described as 'lock nut' - how am I meant to source an equivalent stainless steel version without knowing the size of the nut ?

Also, on PDF page 62, I cannot tell how the Turbo Heat Shield (part 14) is attached the Turbo unit. I can see it goes through a stud (part 29) but not what is secured at the end of the stud ?

Any help/guidance ?

 

[Chris_in_the_UK]

I often use here:-

http://www.deroure.com/diagrams.asp?MAK=3&SMA=0&SMO=0&ST=&SC=0

Parts diagrams are zoomable and the current OPC prices are displayed along with any bolt sizes etc.

 

[richard hall]

I know this wont sound quite that obvious but you do need to be careful which bolts you replace with stainless, A2 is usually car grade however most stainless does not have the tensile strength of steel bolts and although a4 marine might sound the best the extra chromium increases the likelyhood of fatigue if there is no movement A2 is fine also consider galvanic corrosion on that basis it is worth checking the strength of the bolts that are coming out particulalry the turbo and manifold ones

most automotive sizes are m5 m6 and m8, m8 being 13 mm,I had wanted to change the turbo to manifold nuts which are M8 to copper coated steel but in the end went for porsche due to time constraints

2 articles which might help

http://www.volksbolts.com/faq/basics.htm

http://donsnotes.com/home_garden/bolts.html

for stainless bolts/nuts etc i have found these two companies on ebay to be competitive

http://stores.ebay.co.uk/Aruncas?_trksid=p2047675.l2563

http://stores.ebay.co.uk/A-BOLT-FTB?_trksid=p2047675.l2563

for a slightly wider and more specialist selection i found these guys helpful

http://www.accuscrews.co.uk/17-precision-hardware all no afilliation

good luck

 

[Stuart Hardy]

Hi

Richard is spot on. Watch for corrosion between the stainless steel and the surrounding non stainless steel components. Also, A2 grade fasteners will crevice corrode in short order in the hot, damp conditions encountered around an exhaust system. There are some stainless fasteners that are up to the job but they are expensive and not particularly easy to find. Try TR fasteners and ask them for Bumax Fasteners in the sizes you need. These are equivalent to 10.9 grade steel fasteners so should be strong enough and are made from 316 grade stainless steel, which is marine grade. From memory, they are only available in hex socket cap head form, but I might be wrong because that is all we use on the boats.

Be prepared to pay for them. If you think Porsche parts are pricey then you'll get a real wake up call. You might also have to wait for them. Quality doesn't come cheap and these are about the only fasteners that are guaranteed 100% defect free. Coming from Sweden they are probably the only fasteners not made in the USA or India.

Perhaps the best bet is to use GOOD quality alloy steel fasteners with a good zinc or nickel coating and cover them in copperslip.

Regards